Boiler will not fully drain

Robbbbb

Every year, I fully drain the steam boiler and use the 2 bottle Colloid treatment.  This year, only 1/2 of the dirty water drained out.  But it's not clogged.  I can add clean water from the fill line, as water continues to run from the drain.  But the glass level is still 1/3 full of dirty water. 



I tried to drain it from both valves on the boiler. Although I've always had success draining all of the water from the bottom valve.



Thanks



R

freddrow2002

sight glass

does water move in sight glass when filling? make sure both top and bottom valves are open on glass. if they are you could have a block behind valve not letting water drain from sight glass.

freddrow2002

sight glass

does water move in sight glass when filling? make sure both top and bottom valves are open on glass. if they are you could have a block behind valve not letting water drain from sight glass.

nicholas bonham-carter

colloidal problems

is there some reason to put any chemical in the boiler? has this chemical been recommended by the boiler manufacturer?

because of the dissolved oxygen in the boiler, it would be better to leave the same pure water, without additives in the boiler for most of it's life. this colloidal treatment must now have clogged up some of the passages of the boiler, and who knows what else. most likely as stated, the sight-glass, gauge cocks have been plugged shut. there are only a few reasons to add chemicals to the boiler, and the choice of additive depends on a chemical analysis of the local water. if there is a leak which you are trying to control. then the surefire solution is to install new sections in the boiler.

see if you can get that additive cleaned out before it coats the bottom of the boiler sections, causing unequal heating, and cracking of the boiler. check that the pigtail has not closed up as well.--nbc